Reproducing and transmitting device



April 15, 1924. I

A. P. PlNKLER REPRODUCING AND TRANSMITTING DEVICE Filed Feb. 18, 192] 2Sheets-Sheet l April 15 1924- A. P. PINKLER RBPRODUCING AND TRANSMITTINGDEVICE Filed Feb 18.

192-1 2 SheetsSheet 2 I I I t l I b H Patented Apr. 15, 1924.

UNITED STATES PATENT OFFICE.

REPRODUCING AND TRANSMITTING DEVICE.

Application filed February 18, 1921.

To all whom it may concern:

Be it known that I, ARTHUR P. PINKLER, a citizen of the United States,and a resident of Ridgefield, New Jersey, have invented certain new anduseful Improvements in a Reproducing and Transmitting Device, of whichthe following is a full, clear, concise, and exact description.

This invention relates to improvements in reproducing and transmittingdevices, and particularly to an electrical device for reproducing andtransn'iitting musical sounds from a phonograph record.

It is the object of this invention to produce a device of the classdescribed which faithfully reproduces and transmits musical sounds,which is of light but solid construction. and which may be readilyassembled.

Vith this object in view, an electrical transmitter is provided andcomprises comminuted conducting material, such as granu lated carbon,for varying the resistance of an electrical transmission circuit. Inorder to prevent the packing of the carbon granules, one feature of theinvention provides for a carbon granule chamber which is moved orvibrated to create the desired resistance variations. Due to thisarrangement, continuous contact is insured between the carbongranules'and the electrodes forming the terminals of the electricaltransmission circuit, and the distort-ion ofthe musical sounds isprevented.

In accordance with another feature of this invention, a movableelectrode and a carbon granule chamber are comprised in a mechanicalunit, and the unitis vibrated to control the resistance of thetransmission circuit.

According to a further feature of the invention, the transmitter is comosed of two carbon granule chambers, eac having a cooperating stationaryelectrode, a movable electrode being provided in common for the twochambers. Preferably, the movable electrode serves as a partitionbetween the two chambers, and the unit formed by these three elements isvibrated between two stationary electrodes.

These and other features of the invention will more clearly appear fromthe following description of a preferred embodiment of the invention,and the appended claims.

The drawings represent various views of a. reproducing and transmittingdevice. Fig. 1 is a front view of the device; Fig. 2

Serial Np. 445,935.

moved; Fig. 4 is a sectional side view; Fig.

5'is a perspective view of the telephonic element or transmitter; Fig. 6is a sectionalview along lines 6-6 of Fig. 4; Fig. 7 is a sectional viewalong lines 7-7 of Fig. 5; and Fig. 8 is a diagram of the transmissioncircuit.

The transmitter, which is to set up variations of current in accordancewith the markings of an associated phonograph record of the well knownlateral or vertical type, is provided within a casing 1 having removablefront and rear covers 2 and 3, and provided at its top with a screw 4and thumb-nut 5 by.means of which the device may be attached to aphonograph arm in the usual manner. A recessed plate or support 6 isheld within the case 1 by means of screws 7-7.

The mechanical reproducing element is provided at the bottom of thecasing l and comprises top and bottom plates 10 and 11, and a vibratorymember or reproducer 12 within a recess of which a stylus 13 may besecured by means of a thumb screw 14. The plate 11 is fastenedto theplate 10 by means of screws 15, and plate 10 is fastened to the casing 1and support 6 by means of lugs 16 and 17. The lower ends of lugs 16 and17 are wedge shaped and form knife-edge pivots for the top portion ofreproducer 12, engaging grooves 18 and 19 therein. The top of reproducer12 projects through an opening 20 in plate 11 within the space enclosedby plates 10 and 11, and is seated on rubber strips 21, 22 provided onplate 11 adjacent to opening 20.

The transmitter comprises three disk shaped carbon electrodes 30,31 and32. The electrode has a central opening through which a screw 33projects and is received within a sleeve 34. The sleeve 34 projectsthrough an aperture of, a bridge 35 fastened to support 6 by means ofscrews 36, 36, but insulated therefrom by washers 37-37 of any suitablematerial. The electrode 30 is held stationary by means of a screw 38projecting through the bridge 35 and engaging the sleeve 34. Theelectrode 32 is similarly stationed onthe other face of support 6. v

The electrode 31 is located between the two stationary electrodes 30-and'32, and'is held around its perifery within grooves of metal strips41 and 42. The strips 41 and 42 are securely held together' at theirends by rivets 43 or other suitable means, the central portions of thesestrips being bent to form a pocket or circle within which the electrode31 is located. A rib or corrugation 44 runs along the outer surface ofeach strip. On the inner surfaces of these strips, the ribs serve as thementioned groovesAO. The strips 41 and 42 may be made of relativelylight material and structure that receives the necessary stifi'ness.

fromthe ribs. Bearings 45 providedat the upper ends of the strips 41, 42are engaged by pivots 46 projecting within the recessed portion of thesupport 6. These serve as the upper pivot of the transmitter. A wire orarm 47 secured between the lower ends of strips 41 and 42 terminates ina hook-48 engaging a wire 49 stretched between posts 50 provided in thetop portion of 12. The hook 48 is soldered to the wire 49 and serves asthe lower pivot of the transmitter.

The electrodes 30 and 32 are separated from the edges of the circleformed by 41 and 42 by means of felt rings 51 and 52. The two chambersenclosed by the three electrodes and strips 41 and 42, are entirelyfilled with finely granulated carbon or other suitable comminutedconducting material.

When the device is in operation, the vertically or laterally groovedphonograph record vibrates the stylus and the latter causes the rockingof reproducer 12 on the knife edge pivots 16 and 17. The vibrations of12 are dampened by cushions 21 and 22, and through the agency of wire49, hook 48 and arm 47, these vibrations are transmitted to thetransmitter. The electrodes 30 and 32 bein held stationary, only theelectrode 31 an the holding strips 41 and 42 respond to the vibrationsof 12. These elements forming a unit pivoted at its two ends, readilyrespond to the vibrations of 12 and vibrate to compress or permit the'diffusion of the carbon granules in the chambers on the two sides ofelectrode 31. This determines the resistance variations in thetransmission circuit.

This arrangement is particularly adapted to prevent the distortion ofsound vibratlons that may result from lack of synchronism between the oerations of the telephonic and reproducing e ements. The threeelectrodes are continuously in contact with the carbon granulespreventing thereby any interruption in the electrical transmissioncircuit. Due to the fact that the chambers are entirel filled withcarbon granules, and that a re atively large mass (41, 42, 31 and thecarbon granules) is freely vibrated, the danger of the electrode 31ioperating out of synchronism with: the carbon granules is reduced to aminimum. Furthermore, the.

carbon granules are readily responsive to is vibrated and not anelectrode in front of a stationary chamber. The carbon granules arecontinuously subjected to effective shaking whereby their packing isprevented.

The electrical circuit through which the musical sounds are transmittedis illustrated in Fig. 8. 60, 61 and 62 are conductors leading to thethree electrodes. By means of a switch 63, 64, 65 of any suitabledesign, these conductors ma be connected with a receiving set comprisinga battery 66, an induction coil 67 and a tele hone receiver 68. Theprimary winding 0 the induction coil is divided into two sections, a andb, and the current source is connected midway between these twosections. The secondary winding 0 of the induction coil is connectedwith the receiver.

' In assembling the device, first the stri s 41 and 42 are fastenedtogether with t e electrode 31 clamped in place. This assembly ismounted on the support 6 and the hook 48 is soldered to the wire 49.Then one chamber is filled with granular carbon, the felt washer 51 putin place and the electrode 3O laid thereon. The bridge 35 is now screweddown and the electrode 30 fixed in its properly adjusted osition b meansof screw 38. Then the other cham er is filled and the electrode 32adjusted. The stationary electrodes are always easily accessible forcorrecting their adjustment.

What I claim is:

1. An electrical transmitter device, comprising a movable electrodeproviding upon its opposite sides chambers for holding comminutedconducting material, and stationary electrodes upon either side thereofto retain therein the comminuted material.

2. An electrical transmitter device, comprising two separate andclamping members and a conducting wall held thereby, said membersproviding chambers upon opposite sides of the wall for holdingcomminuted conducting material and constituting with the wall a movableelectrode, and stationary electrodes upon either side thereof to closethe chambers and retain therein the comminuted material.

3. An electrical transmitter device, comprising two movably mountedstrips of relatively light material and secured together, a diaphragmheld thereby to provide two chambers for holding comminuted conductingmaterial, and stationary electrodes upon either side thereof to retaintherein the comminuted material.

4. An electrical transmitter device, comprising two movable strips oflight material secured together and having a longitudinal rib along themedian plane of each strip and a corresponding groove along the innersurface, and a diaphragm held in the said groove, the same constitutinga movable tionary electrodes upon either side thereof.

5. An electrical transmitter device, comprising a movable electrodeproviding 6 upon its opposite sides chambers forholding commmutedconducting material, stationary electrodes upon either side thereof toretain therein the comminuted material and a stylus adapted tocommunicate movement to the movable electrode.

6. In an electrical transmitter device, two strips of relatively lightmaterial held together at their ends, a. rib along the outside surfaceand a corresponding groove along the inside surface of each strip, anelectrode held in'thegrooves of the strips intermediate the endsthereof, a carbon granule chamber on each side of said electrode, thewalls of said chambers being constituted by said electrode and strips, asupport, two electrodes fixed thereto, each constituting the enclosingwall of one of said chambers, and a pivotal suspension for one end ofsaid strips on said support.

7. In an electrical transmitter device, two strips of relatively lightmaterial held together at their ends, a rib along the outside surfaceand a corresponding groove along the inside surface of each strip, anelectrode held in the grooves of the strips intermediate the endsthereof, a carbon granule chamher on each side of said electrode,the'walls of said chambers being constituted by said electrode andstrips, a support, two electrodes fixed thereto, each constituting theenclosing wall of one of said chambers, a pivotal suspension for one endof said strips on said support, a reproducer, and a stylus thereforconnected with said strips.

8. In a reproducin and transmitting device, two strips of re ativelylight material held together at their ends, a rib along the outsidesurface and a corresponding groove along the inside surface of eachstrip, an electrode held in the grooves of the strips intermediate theends thereof, a carbon granule chamber on each side of said electrode,the walls of said chambers beingconstituted by said electrode andstrips, a support, two electrodes fixed thereto, each constituting theenclosing wall of one of said chambers, a pivotal suspension for one endof said strips on said support, a reproducer, a stylus therefor, a platefastened to said support, strips of cushioning material thereon seatingsaid reproducer, a mechanical connection between said reproducer and theother end of said strips, knife-edge pivots for said reproducer on saidsupport, and electrical connections to said electrodes.

In witness whereof I have hereunto set my handthis 17th day of February,1921.

ARTHUR P. PINKLER.

